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Objective To assess the inter-scanner reliability and reproducibility of 3D whole-brain pseudo-continuous arterial spin labeling (pCASL) of posterior circulation territory in healthy adults.Methods Twelve healthy subjects were scanned twice on two different 3.0 T MR scanners with 3D wholebrain pCASL technique.Intervals between tests were among 10-15 days.The ASL data with two post labeling delay time (PLD) of 1.5 and 2.5 seconds were acquired during every scanning.The cerebral blood flow (CBF) values of posterior circulation territory including cerebellum,midbrain,pons,medulla oblongata,thalamus and occipital lobe were extracted based on SPM technique for comparison.The interscanner reliability and reproducibility were evaluated with the intraclass correlation coefficient (ICC) and Bland-Altman plot.Results The CBF values of posterior circulation territory were 36-47 ml · min-1 ·100 g-1 (PLD =1.5 s) and 36-46 ml · min-1 · 100 g-1 (PLD =2.5 s).Comparing the data between the two tests,the ICC was 0.851 at PLD =1.5 s and 0.914 at PLD =2.5 s.The Bland-Altman showed the reproducibility at PLD =2.5 s was better than that at PLD =1.5 s.Conclusions The 3D whole-brain pCASL technique is available for measuring the CBF at posterior circulation territory with high reliability and reproducibility especially using longer PLD.It can be used for MR multicenter study on blood flow of posterior circulation territory.
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ObjectiveTo investigate MR imaging features of endolymphatic sac and vestibular aqueduct in patients with large vestibular aqueduct syndrome (LVAS) and its correlation with hearing loss.MethodsMR imaging findings of LVAS were analyzed in 31 cases (62 ears) retrospectively.MR imaging features were grouped into 4 types.In the first type,the signals of endolymphatic and vesitibular aqueduct were hypointense without any hyperintense area.In the second type,the signals of endolymphatic sac and vestibular were hyperintense which were confined within vestibular fissure.In the third type,the area from vestibular aqueduct backward out of the edge of the petrous bone was hyperintense,but its lower boundary was above posterior semicircular.In the fourth type the area which was hyperintense was below the posterior semicircular.To avoid errors in visual inspection,the hyperintense and hypointense area of endolymphatic and the signal intensity of vestibular aqueduct and cerebrospinal fluid (CSF)were measured.The differences of signal intensity among the vestibular endolymphatic sac between the high-signal areas and lowsignal areas were compared with paired t-test.The correlation of the endolymphatic sac MRI classification and degree of hearing losswasanalyzedby correctedChi-squaretestandSpearmancorrelation analysis.ResultTen ears belonged to type Ⅰ (moderate hearing loss in 1 ear,severe in 4 ears,profound in 5 ears),17 ears belonged to type Ⅱ ( moderate hearing loss in 1 ear; severe in 5 ears,profound in 11 ears),23 ears to type Ⅲ (moderate hearing loss in 3 ear,severe in 5 ears,profound in 15 ears) and 12 ears belonged to Ⅳ(mild hearing loss in 1 ear,moderate in 1 ear,severe 3 ear,profound in 7 ears).The boundary between hyperintense and hypointense area was clear,and the signal intensity ratios was 2.02 ± 0.06.The signal ratios of hyperintense and hypointense area to vestibular and CSF were 0.95 ±0.12,0.49 ±0.10,0.99 ± 0.08 respecitively.So there was statistical significant difference between hyperintense and hypointense area ( t =- 24.966,P ＜ 0.05 ),but there was no statistical significant difference between hyperintense area and vesitbular( t =-24.966,P ＞ 0.05).There was no difference of hearing loss between different MRI types ( likelihood ratio =5.02,P ＞ 0.05 ).Conclusions Not only endolymphatic sac enlarged but also perilymph herniated into skeletal fissures of vestibular aqueduct in patients with LVAS.The signal intensity of the endolymphatic sac did not show significant correlation with degree of hearing loss.
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BACKGROUND:The cervical pedicle screws mistakenly inverted the cervical pedicle could lead to the many complications such as spinal cord,vertebral arteries and nerve root damage.If the parameter of inserting pedicle screws were measured accuracy,the rate of inserting pedicle screws successfully could be improved.OBJECTIVE:To get 3D anatomic parameter of inserting pedicle screws in the cervical vertebrae with the CT three-dimensional recontruction.METHODS:The Dicom data that the cervical vertebrae had been scanned by SIEMENS EMOTION 16 CT were converted into the soft Mimics 8.1,GE workstation and three-dimensional cervical vertebrae were reconstructed.The parameters of inserting cervical pedicle screws were measured with the consideration of the diameter of pedicle screw.RESULTS AND CONCLUSION:The cervical three-dimension images were reconstructed clearly with the CT three-dimensional reconstruction techniques.The cervical pedicular width,the axial length,α and β angles were measured by the soft measure function.The average inserting angular safe range of α angle was gained with the consideration of the diameter of pedicle screw.This method can mimic the operation and it is significant way in measuring the three-dimension anatomic parameter of the cervical vertebrae.The method is a good way that how to insert the cervical pedicle screw safely.
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BACKGROUND: Differences of thick and thin tissues in imaging areas is great because of postero-anterior images in cervical spine-thoracic spine.Although there are many image processing functions in direct digital radiography(DR)image with big range dynamic exposing,but routine direct DR hardly reveals anatomic structure of cervical spine-thoracic spine to detect diseases.Image quality of cervical spine-thoracic spine requires improvement.OBJECTIVE: To evaluate the difference between direct DR image with tissue equalization(TE)technique and standard DR in cervical spine-thoracic spine,so as to explore the best image quality in cervical spine-thoracic spine.METHODS: A total of 200 cases were randomly selected from DR cervical thoracic image from Department of Radiology,General Hospital of Chinese PLA between April 2005 and August 2009 to evaluate the difference between these images of DR processed by tissue equalization and that of standard DR.RESULTS AND CONCLUSION: The detail images of DR with tissue equalization in different thickness area of body could be revealed clearly in the same image,while the detail images of standard DR in cervical thoracic could be revealed clearly by adjusting window width and location repeatedly.Results show that the image quality of TE technique of direct digital X-ray radiography in cervical spine-thoracic spine could be clearly improved,it could be easily read and avoid the influence of body thickness area.Moreover,it could reveal clearly other part of body in detail.DR image with TE technique in cervical spine-thoracic spine can be applied widely due to simple operation,high diagnosis rate and low cost.
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0.05) . Conclusion An acceptable image quality can be achieved for pediatric patients by reducing the mA value to 40 to 80mA used for conventional temporal bone, and the low dose CT scanning ought to be extended in the temporal bone decease for children.
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Objective To investigate the CT and MRI value in diagnosis and clinical manifestations of liver tumor in child. Methods 13 cases of surgically and pathologically confirmed liver tumor were retrospectively analyzed that 11 males, 2 fe- males, age range from 13 months to 14 years, average age 10.8 years. Contrast CT was undertaken in 10 patients and MRI in 6 patients. Results In all cases comprised primary hepatocellular carcinoma 7 cases(8%), hepatoblastoma 3 cases(23%), leukemia involved liver 1 case, cavernous hemangioma 1 case, hepatic mesenchymal hamartoma 1 case. Different type of tumor had its own imaging manifestations. Conclusion CT and MRI can precisely delineate the location, size, extent of in- volvement. It provides an important basis of clinical staging for tumors prognosis and treatment.
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Objective To investigate the value of optimizing the thoracic CT scanning dose on reducing radiation dose.Methods 50 patients were undergone CT scanning using CARE Dose 4D technique,the mAs of each slices,CT dose index of volume(CTDIvol) and images qualities were evaluated respectively.And the results were compared with traditional thoracic CT scanning(200mAs,15.31mGy).Results Compared with routine sequence,the exposure dose of singe-slice was decreased by 48.2% when the CARE Dose 4D technique was used(maximal decreasing 84%),CTDIvol was reduced about 32.98%(maximal reduction of 56.5%),there was statistically significant difference(P